I think the ziploc should be fine....though I have in the past gotten people at local petsmarts and petlands to give me a few of their bags. I like using them when I can because they don't have sharp corners for the fish to get stuck in (but on the occasions that I HAVE used ziplocs, the fish have never been injured).
I'm not sure from your post if you were just asking about the bags or wanted general moving advice....so I'll give you some just in case, and if it's helpful, then great........
Here's how I move fish....and I do this whenever I'm moving anyone...be it from fish store to aquarium or aquarium to aquarium.....
1) float the bag for about 20 minutes to a half an hour (the bag should be closed- you don't want to contaminate the tank with whatever might be in the water.)
2) then I open the bag and dump the fish and its contents into a large glass mixing bowl set on a chair next to the tank
3) take a length of plastic air tubing and set it up to siphon tank water from the aquarium into the glass bowl.
4) start siphoning- but as soon as water starts coming out, tie a knot at the bottom of the tubing, so that the water flow is reduced to a steady drip.
5) leave the whole set up like this, with the tank water dripping into the glass bowl for at least an hour, sometimes two.....basically until most of the water in the bowl is the aquarium water the fish will be moving into.
6) finally, net the fish and transfer him to his new home
7) replace the lost tank water with some fresh water from the tap (or wherever you get your water from).
I've never lost a fish as a result of stress from an aquarium introduction. That's my method....hope it was helpful.